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[16:00:17]

JAKE TAPPER, CNN ANCHOR: Hillary Clinton touching down a short while ago. You can see her there just after she deplaned here in the City of Brotherly Love.

It is day three for Democrats in Philadelphia. The president and vice president will be here, hoping they can pass the baton this evening.

I'm Jake Tapper. This is THE LEAD. We're live from the Democratic National Convention in the beautiful city of Philadelphia.

President Obama is again getting ready to take the big stage in prime time. This is of course 12 years after the convention for John Kerry in Boston, where the then state senator talked about the hopes of a skinny kid with a funny name who believes that America has a place for him, too.

Can the president convince those listening and watching this evening that Hillary Clinton is the heir to the hope and change he promised when he took office? Bill Clinton last night called his wife the best darn change maker he has ever known. He tried to make the most famous couple in American politics seem kind of ordinary, opening a window into a marriage that many find complicated and sometimes difficult to understand.

Today, with reports moving on from the WikiLeaks release of e-mails hacked and stolen from the DNC server and headlines blaring the word historic about Hillary Clinton's nomination, Donald Trump earlier pooh-poohed those cyber-security experts pointing the finger at Russia for the hack into the DNC server.

And then -- well, then he said this.

(BEGIN VIDEO CLIP)

DONALD TRUMP (R), PRESIDENTIAL CANDIDATE: Russia, if you're listening, I hope you're able to find the 30,000 e-mails that are missing. I think you will probably be rewarded mightily by our press.

(END VIDEO CLIP)

TAPPER: Trump supporter Newt Gingrich said Mr. Trump was joking. And campaign officials say all Mr. Trump was doing was asking anyone who might have those e-mails, the Russians, the Chinese, a hacktivist group, to hand them over to American law enforcement.

But many Democrats and even some Republicans and other national security experts say it sure didn't sound that way to them. It sounded kind of like the Republican presidential nominee asking a rival nation to commit espionage. And, by the way, that espionage might no doubt help him defeat Hillary Clinton.

We're looking at live pictures right now of Donald Trump. He just touched down in Scranton, Pennsylvania, about 120, 130 miles away from us here in Philadelphia. And we're going to monitor that to see if he tries to explain what exactly he meant by his comments this morning which have, needless to say, rocked the political world.

Chief political correspondent Dana Bash joins me now.

Dana, tonight, it will be the Obama administration attempting to vouch for Hillary Clinton. Eight years ago, need I remind everyone, the president and then Senator Clinton were trying to put salves on the wounds that they each caused each other.

Will we hear any admission by President Obama that he was not always so fond of the woman he ended up putting in charge of his State Department?

DANA BASH, CNN SENIOR CONGRESSIONAL CORRESPONDENT: I'm guessing that probably made the cutting room floor and won't actually be in the speech.

But I am also assuming he will address the fact that he knows Hillary Clinton not just as a secretary of state, and as a friend, but as a former competitor. But what Barack Obama will be doing is trying to convince Americans to make history, not just because they would be electing the first female president following the first African- American president, but because history is not on Hillary Clinton's side when it comes to the concept of a third Democratic term, or a third term of any party for that matter.

That last time that happened was when George H.W. Bush won in 1998 following Ronald Reagan's two terms, and before that the Democrats, Harry Truman Back, back after World War II, in '48, he was the last one, last Democrat to succeed another Democrat. Of course, that was FDR.

My point here is that Barack Obama, his whole goal is to keep his legacy going, and he thinks the best way to do that is with Hillary Clinton. But he understands it is not going to be easy to do. Our understanding is he will talk about that, but also talk about Hillary Clinton, the person, and Hillary Clinton, the potential commander in chief or why he thinks she has the ability to do that because he's there right now -- Jake.

TAPPER: All right, Dana Bash, thank you. The theme of this evening at the Democratic Convention is security. Donald Trump earlier today tried to preempt and prebut the case the Democrats will try to make that Hillary Clinton will be a good steward of American security.

CNN's Jeff Zeleny joins me now on the convention floor.

Jeff, Republicans have criticized the convention for initially at least barely mentioning the terrorist threat, barely mentioning ISIS. I assume that is not going to be the case this evening.

[16:05:05]

JEFF ZELENY, CNN SENIOR WASHINGTON CORRESPONDENT: That will not be the case this evening, Jake.

We are told that tonight, the speeches really from beginning to end will have a theme and a thread of keeping America safe. And what a lineup there is tonight in terms of former respected members of the administration.

Leon Panetta, the former director of the CIA, the former secretary of defense, we are told now, will be delivering a robust response to Donald Trump and his comments earlier today about Russia. Right here on this stage tonight, he will be developing and delivering that response.

And that's not alone. Vice President Biden also, we're told, will respond about the seriousness to which the Democrats should take this argument, will not mention Donald Trump by name. But President Obama also will talk about the ISIS threat.

But Tim Kaine, this will be his maiden speech here before this Democratic delegation, the delegation from Virginia right behind me here.

He will give a more personal anecdote about his son Nathaniel, who has just been deployed. He's in the Marines. He will talk about his service on the Senate Armed Services Committee, the senator's, as well as their own sacrifice here.

Jake, tonight throughout the evening, I'm told, will be terrorism security, certainly a different tone, a turning of the page, from the internal disputes with Bernie Sanders, Hillary Clinton to one of protecting the country. There will be much criticism about that, but Donald Trump, I'm told, has really changed the program a little bit tonight.

He was trying interrupt the Democratic Convention a bit, and he may just have given them something else to talk about here tonight -- Jake.

All right, let's start, Andre. Please explain the comments. It sounded to a lot of national security officials, Democrats, and even Republican officials as though he was glibly suggesting that a rival nation commit espionage on our former secretary of state.

LT. GOV. ANDRE BAUER (D), SOUTH CAROLINA: Well, again, I can't think of Donald Trump. I have not talked to him. I don't really have any conversation with him, but I think it again is tapping into the distrust, the anger the American people have.

They feel like they were slighted on the whole e-mail server situation. I think probably out of frustration, he says yes, he is being blamed now for several days that he has contacts with Russia, he had something to do with this. And he probably out of frustration said, look, if Russia has the goods on her, we would like to see it. Give it to the media. Turn it over.

That would be what I would think.

GLORIA BORGER, CNN SENIOR POLITICAL ANALYST: But this is a hack of the Democratic National Committee that our intelligence people now believe was perpetrated by the Russians.

I was talking to a former national security official today, and he said to me that it converts the collection of information, which is what we all do, right, into an actual covert operation program, and that the worry in the intelligence community about Donald Trump is that either he gets it and he thinks it's OK, or he doesn't get it, which is also a worry for them.

The question is, if he didn't mean to say, OK, I'm on Russia's side, then he ought to say that.

BAUER: I don't think he ever said he was on Russia's side.

BORGER: Of course not, so shouldn't he say that, though, and say this is wrong to hack the Democratic National Convention?

MICHAEL NUTTER (D), FORMER MAYOR OF PHILADELPHIA: Why re-raise the issue in the first place? As Gloria said, this is about the Russians, potentially, and the DNC.

What does that have to do with Hillary Clinton? Nothing. What's the point?

TAPPER: I guess the issue is...

NUTTER: And it's cute, but it's...

(CROSSTALK)

BAUER: I think it hurts Hillary Clinton more than anybody.

(CROSSTALK)

TAPPER: This is a different e-mail controversy, right? This is the Hillary Clinton e-mail scandal vs. the DNC. He's conflating the two.

Just for people who may not have followed the e-mail server story all that closely, there are 33,000 e-mails that Hillary Clinton had that she said were personal and were deleted, therefore she could not turn over to the State Department. Those are the ones that Donald Trump is saying, hey, Russia, if you can get them and release them to the press.

S.E. CUPP, CNN POLITICAL COMMENTATOR: Yes, but the problem is he doesn't ever the geopolitical consequences of the things that he says.

Whether he says he might not be protecting NATO as much if he were president, or that he might not protect the Balkans as much if he were president, or this, there's no sensitivity. There's no natural ear for any of these issues.

Let's pretend for a second that it's sinister, and he actually does know what he is saying. Well, that is awful. I actually think he just doesn't know enough to know the difference, which is equally worrisome.

NIA-MALIKA HENDERSON, CNN SENIOR POLITICAL CORRESPONDENT: I also think, just in terms of if you're a Republican strategist, it looks like this was a time that Donald Trump could have gone on the offense, right, talk about cyber-warfare, talk about Hillary Clinton's e-mails, talk about the DNC and what appeared to be collusion with some of those folks.

But instead he stepped on his own message and made it worse.

[16:10:00]

TAPPER: We're going to -- let me just take a quick break, because we have to pay some bills now, but don't worry. I'm going to come to everybody on this issue.

The third day on the Democratic National Convention just a few minutes from getting under way, and we're going to bring that to you live, including vice presidential nominee Tim Kaine's official nomination as the nominee.

Stay with us.

(COMMERCIAL BREAK)

TAPPER: Welcome back to THE LEAD. We're here in Philadelphia.

Let's get right back to our panel.

And just to remind viewers of the big news today, a comment made by Donald Trump talking about questions about whether or not Russia hacked into the Democratic National Committee e-mail server and released those e-mails via WikiLeaks last week. In talking about it today, earlier today in Florida, he also talked about Hillary Clinton's e-mail server scandal and then he said this:

[16:15:00] TAPPER: All right. Well, for some reason, we don't have that bite cued up. He said, "Russia, if you're listening, I hope you're able to find the 30,000 e-mails that are missing. You'll be rewarded mightily by our press."

DAVID GERGEN, CNN SENIOR POLITICAL ANALYST: Well, the Democrats have had two really good nights, big nights, have big audiences than the Republicans had in first two nights. And now along comes Donald Trump and huge gift going into their third night. At the very night they want to talk about safety and security of the United States can make this gaffe. I think Newt Gingrich put the best face on he could about this.

But even so, it opens the door to these charges that he is reckless. That he keeps -- as he has been on NATO in the last week, really dangerous stuff coming out of his mouth. And that really reinforces the Democrats tonight to be able to make that message. You may not love her, you may not love her, but at least you will be in safe hands. At least the country will be in steady hands, and that is a huge gift to the Democrats.

TAPPER: Michael?

MICHAEL SMERCONISH, CNN POLITICAL COMMENTATOR: He's bungled what could have been game changer. And I've been saying and thinking this whole week, if the Russians hacked the DNC computers, that many are saying, many in here are wondering, could they also have hacked into the private e-mail servers in Chappaqua. If an email were to surface --

TAPPER: The FBI has said they can't rule it out.

SMERCONISH: Correct.

That Comey statement was very carefully written. And you'll remember, Jake, that they did say that those in communication with Secretary Clinton were hacked, but they couldn't say for sure about her communications. So, I assume that and it's a big assumption, but assume that an e-mail were to surface in the fall that came from a private server that was the public's business, which she had erased, it would be proof positive that by going the route she had, she jeopardized national security.

But now, with the statement that he made, he looks complicit in all of this. He looks more like he's on the side of the Russians than he is on the side of the United States, and therein lies the problem.

TAPPER: Van, I have to say, there is in this, I mean, Andre was saying that this is bad for Hillary Clinton. And I don't -- I mean, I recognize that that is, to a degree, the view of somebody that supports Donald Trump, but there is implicit in this. If you say that 33,000 e-mails of Hillary Clinton said were personal in nature, if you say that is a national security issue, A, you're acknowledging that her private e-mail server put national security at risk, and, B, you're acknowledging that those, quote, "personal e-mails" were not necessarily personal e-mails.

Is there not a risk here to a degree? I'm not supporting what Donald Trump said, but is there not a double sword here?

VAN JONES, CNN POLITICAL COMMENTATOR: Well, right now, we're acting like Donald Trump is losing. Donald Trump is winning right now because we keep saying Hillary Clinton e-mail, Donald Trump, Russia, Hillary Clinton. And what all this does is continue this sort of, you know, a feeling of concern about the server. That's what he is trying to do. We're kind of falling for it.

That I'm concerned about this for more than just political reasons, we entered a new stage in world history where cyber war is war. Cyber war is war. Lives can be lost.

And for anyone to come on the national stage and invite our enemies to attack us at that level is incredibly dangerous and irresponsible.

And so, listen, beyond the -- look, I think he basically figured out a way to get himself in the news cycle, that is what he wants to do. But he is once again proving that he has zero concern and consideration for the American people.

MICHAEL NUTTER, CNN POLITICAL COMMENTATOR: And it goes back to something that he said earlier. There is a lack of maturity in his comportment -- and how he conducts himself, to just say anything. There are just some things you don't say. You don't glibly talk about having a bomb on an airplane.

TAPPER: Right.

NUTTER: That's not funny, that's not being glib. That is being reckless.

(CROSSTALK)

TAPPER: I didn't joke about a bomb on an airplane, Mr. Mayor.

NUTTER: He seems to not understand that this is not a game anymore.

TAPPER: Stick around. We got more to talk about we come back, the start of day three of the Democratic National Convention. Senator Tim Kaine about to be officially nominated as the Democratic vice presidential nominee, and we'll have that for you live, next.

(COMMERCIAL BREAK)

[16:23:50] TAPPER: Welcome back to THE LEAD.

It's day three and it's officially under way now, live from the Democratic National Convention, at the Wells Fargo Center here in Philadelphia. And behind us right now, the invocation is going on after a call to order.

The Reverend William Byron, founding director and former chairman of Bread for the World, is talking right now.

Let's switch gears and talk a little bit about what we expect to hear this evening and what you think, what you're looking forward to, Nia Malika, what do you think is the most important event this evening?

NIA-MALIKA HENDERSON, CNN SENIOR POLITICAL REPORTER: You know, I think it's going to be President Obama, I think that's why most people is going to tune in. I talk to a lot of folks who looked at Michelle Obama and very much kind of felt sad and wistful about the end of the Obama era, and seeing that as sort of a capstone. I think a lot of Americans are going to tune to see what he has to say as well, what he has to say about Hillary Clinton, what kind of case he makes. We saw Bill Clinton make a very personal case. We expect, I think, from President Obama to hear about her professional experience in the White House as secretary of state.

I thought what was most effective about Bill Clinton is that he put her in different places throughout her life. You know, working at Yale, working to sign up people to vote, voter registration, working with children.

[16:25:07] And I expect that Obama will do the same thing and flesh out her secretary of state tenure and put her in a Situation Room I'm sure.

TAPPER: And, Michael Smerconish, we're also going to hear from Vice President Joe Biden, son of Scranton, Pennsylvania. And we are expecting to hear from him first of all, an address -- the presentation of the colors is going on. We'll take a break when we get to the Pledge of Allegiance.

Michael, one of the criticisms of this convention is there has not been any or many I should specific addresses to white working class voters.

SMERCONISH: Here it comes tonight.

TAPPER: And Joe Biden -- Vice President Joe Biden, son of Scranton, we expect that he will make such an appeal.

SMERCONISH: He is as perfectly suited I think as anyone who will address this convention to do so. My parents' roots are in that part of northeastern Pennsylvania coal crackers and that I think that he meets all of the demographic needs to be able to address that crowd. That's his natural constituency and I think that's where he'll go.

I listened to the speeches last night, and it was as if each speech had a designated audience that was part of the core Democratic constituency. Biden will hit that group tonight.

TAPPER: Here comes the Pledge of Allegiance. So, we're all going to stand up and we're all going to watch.

TAPPER: Sebastien De La Cruz, a 14-year-old mariachi singer, born and raised in San Antonio, Texas, and a son of a navy veteran. You might remember when he was 11, he sang the national anthem at the NBA finals in 2013 and he faced something of a racist backlash on social media.

Congresswoman Marcia Fudge will now come out and we will begin the proceeding, putting Senator Tim Kaine of Virginia, his name into nomination to be the vice presidential nominee for the Democratic Party.

REP. MARCIA FUDGE (D), OHIO: Ladies and gentlemen, pursuant to our procedural rules, the convention secretary has received nominating documents for one Democratic candidate for the office of vice president of the United States, Senator Tim Kaine.